The logic of the IsContentPreserved (inherited from RadTabControl) property could be implemented in RadOutlookBar

Available in LIB version 2017.3.1113, it will be also available in the R1 2018 Release.

The style of the items that are contained in the dropdown content of the overflow button cannot be edited.

The Metro theme isn't properly applied on the RadOutlookBarItems if it is set in the RadOutlookBar definition:
<telerik:RadOutlookBar telerik:StyleManager.Theme="Metro" />

When the OutlookBar is minimized during run-time change of themes the text set to item's header overlaps the minimizing toggle button.

You can work this around by creating a custom control that derives from RadOutlookBar and override its OnApplyTemplate() method. Inside the method call the protected VisualStateChanged() method.

public class CustomOutlookBar : RadOutlookBar
{
	public override void OnApplyTemplate()
	{
		base.OnApplyTemplate();
		this.ChangeVisualState(false);
	}
}

Available in the R1 2017 SP1 Release.

Add Style for easier customization of the Vertical / Horizontal resizers

If you set the SmallIcon property of a RadOutlookBarItem and you minimize the item the icon will not be visualized. Note that the icon is not visualized when a certain item goes in the popup.

This happens  whether there is available space in the active area are not. All items are rendered in the minimized area.

To work this around you can set the IsContentPreserved property after the control is loaded.


The fix for this issue will be available with the next LIB (version 2018.3.1224) expected on Monday, December 24.

When the control is in minimized state and the items do not have an icon, the headers are not visible.

The foreground of the MinimizedButton and minimizeable arrow in Expression_Dark theme is wrong. The issue appears when the OutlookBar is minimized and the minimized button is clicked

As a workaround, you can add a custom Margin and Padding to the MinimizedOutlookBarItems:

<Style TargetType="outlookBarPrimitives:MinimizedOutlookBarItem">
    <Setter Property="Padding" Value="5" />
    <Setter Property="Margin" Value="2" />
</Style>

Where xmlns:outlookBarPrimitives="clr-namespace:Telerik.Windows.Controls.OutlookBar;assembly=Telerik.Windows.Controls.Navigation".

ItemTemplateSelector does not work. 

There is a workaround to extract the control template and edit the HeaderElement style with:
<ContentControl.ContentTemplateSelector>{TemplateBinding HeaderTemplateSelector}</ContentControl.ContentTemplateSelector>

The problem is fixed and will be available with Lib 2016.3.926.